The instant invention relates to transformer couplings for transmitting direct current from an energy source on one side of an electrical and mechanical barrier to a load on the other side of the barrier. More particularly, the instant invention relates to such a coupling wherein optical feedback is utilized to regulate output voltage.
It is frequently desirable or necessary to transmit electrical energy through an electrically and mechanically impervious barrier. The conventional approach is utilize electrical connectors. However, electrical connectors cannot maintain seal integrity in many situations and are susceptible to tampering. Other approaches utilize mechanical switch contacts or motor generator arrangements to effect energy transfer across electrical and mechanical barriers; however, such arrangements, while not necessarily accident prone, are not accident proof either. Accordingly, there is a need to provide an arrangement for transferring energy across barriers safely in hazardous environments, such as environments in which nuclear materials, explosives or toxins are present.
While there are a number of patents which disclose magnetic couplings between transformers, none of these patents disclose an arrangement for selectively passing or blocking magnetic coupling between transformer windings by using a mechanically moveable coupling. For example, U.S. Pat. Nos. 4,236,196 and 4,210,947 relate to a switching regulator design wherein a pulse-width modulation scheme is disclosed in which physical movement of a core is used to cause saturation and increased current. The increased current is sensed by an oscillator circuit used to shut off the oscillator drive. In these patents, magnetic isolation of transformer sections is not disclosed. U.S. Pat. Nos. 4,041,364 and 4,236,196 disclose shielded transformer designs directed to suppressing radio frequency interference from inverter switching transients. However, in these patents there is no disclosure of magnetic shielding between windings or control of the magnetic coupling between windings. U.S. Pat. No. 3,824,129 discloses a battery and regulator coupled through a pair of RF coils but contains no disclosure of magnetic iron circuitry or of shielding. These same general considerations are applicable to the disclosure of U.S. Pat. Nos. 4,031,496 and 3,921,114.
In view of the aforementioned considerations, there is a need for an improved approach for transmitting electrical energy across a mechanical and electrical barrier.